The present invention relates generally to sports training device and method, and is particularly concerned with a device for use in hitting practice in sports where a club, bat or other ball hitting implement is swung to hit a ball or other object.
One well known problem in swinging a bat or club to hit a ball in sports like baseball or golf is that of hitting the ball from the top or hitting the ball too soon, so that it will not travel as far. In other words, for an ideal swing, no effort should be made to move the hands, wrists, or arms to make the club or bat move. Instead, the movement of the club or bat should result from the player turning their-shoulders and the hands should move with the club or bat, i.e. not faster or slower than the bat.
Many publications on ideal golf or baseball swings refer to the so-called “Magic Triangle” or “Eternal Triangle”. This is a triangle formed by the player's leading arm, the golf club or baseball bat, and an imaginary line between the player's leading shoulder to the approximate hitting end of the bat or golf club. For optimum results, this triangle should be maintained from the top of the swing almost up to the hitting area. This will produce a high speed impact with the ball, as described in detail in the book Four Magic Moves to Winning Golf by Joe Dante, pages 102 to 110, Doubleday, New York, 1995. This is a result of the conservation of angular momentum, which is the principle that the angular momentum of an object remains constant as long as no external force or moment acts on that object. The equation defining angular momentum is:angular momentum=mass×velocity×distance (from point object is spinning or orbiting around).In other words, when an object rotates around a fixed axis (when hitting a ball, this is the vertical axis of the player rotating to hit the bill), it rotates at a constant velocity as long as the object remains at the same distance from the axis. If the object is brought closer to the axis, it speeds up. If it is moved farther out, it slows down. In a golf swing, as the player rotates the club, the hands move farther from the body or axis and slow down. This reduction in momentum feeds into the much lighter club and increases the speed of the club head in the last part of the stroke, in a whiplash type of effect, increasing the force of impact on the ball. If the player speeds up their hands in an attempt to catch up with the club, this effect will be lost, reducing the distance that the ball will travel.
Although this effect has been understood in the golfing field for many years, it is very difficult for a beginning or average player to achieve. This is because there is an instinctive desire to manipulate the club in order to make the club head go faster. Even though the player has been told not to move his or her hands or snap his or her wrists in an attempt to speed up the club head during the latter part of the swing, it is very difficult to restrain the impulse to do just that, resulting in hitting the ball too soon or hitting from the top.
Many training devices have been proposed in the past in order to improve a golfer's or baseball player's swing, with limited success. One is simply to strap one or both arms to the player's body, so as to limit arm movement. Such devices are described, for example, in U.S. Pat. No. 4,960,280 of Corder, Jr., U.S. Pat. No. 5,154,416 of Smull et al., and U.S. Pat. No. 5,295,690 of Johnson. U.S. Pat. No. 5,174,575 of Leith et al. describes a device for tethering the golf club to the wearer's arm, to ensure that the golfer's wrists will pass through the plane of impact before the club head strikes the ball.
The principle and advantages of the delayed hit or late release are well known in the golfing and baseball field, as are the disadvantages of casting, hitting from the top, or early release, in which a player releases their stored energy too early in the swing. Although these principles are well known in the ball hitting field, up to now there has been no simple and effective device for training players in the proper stance and swing positioning for achieving the delayed hit or late release.